Pagini recente » Rating Dulgheru Ion (id18_v) | Cod sursa (job #1004866)
#include <fstream>
#include <vector>
#include <queue>
#define INF 1<<30
#define NMax 50005
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int N,M;
int D[NMax];
bool InQ[NMax],NegativeCycle;
int NrQ[NMax];
vector <pair <int,int> > G[NMax];
queue <int> Q;
void Read()
{
int i;
f>>N>>M;
for(i=1;i<=M;i++)
{
int x,y,c;
f>>x>>y>>c;
G[x].push_back(make_pair(y,c));
}
}
void Solve()
{
int i;
for(i=2;i<=N;i++)
D[i]=INF;
Q.push(1);
InQ[1]=1;
NrQ[1]++;
while(!Q.empty() && !NegativeCycle)
{
int nod=Q.front();
Q.pop(); InQ[nod]=0;
for(i=0;i<G[nod].size();i++)
{
int vecin=G[nod][i].first;
int cost=G[nod][i].second;
if(D[vecin]>D[nod]+cost)
{
D[vecin]=D[nod]+cost;
if(InQ[vecin]==0)
{
Q.push(vecin);
InQ[vecin]=1;
NrQ[vecin]++;
if(NrQ[vecin]>N)
NegativeCycle=1;
}
}
}
}
}
void Print()
{
int i;
if(NegativeCycle==1)
{
g<<"Ciclu negativ!\n";
return;
}
for(i=2;i<=N;i++)
g<<D[i]<<" ";
g<<"\n";
}
int main()
{
Read();
Solve();
Print();
return 0;
}